2-(2H-benzotriazol-2-yl)-4,6-ditertpentylphenol

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study but with restrictions (no GLP, only few details on experimental procedure, E. coli was not included to detect cross-linking, in experiments with metabolic activation a positive control was only investigated in TA1535)

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Reference 2

Reference Type:

publication

Title:

Unnamed

Year:

2001

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

(E.coli was not included, only few details on experimental procedure, in experiments with metabolic activation a positive control was only investigated in TA1535)

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2-(2H-benzotriazol-2-yl)-4,6-ditertpentylphenol

EC Number:

247-384-8

EC Name:

2-(2H-benzotriazol-2-yl)-4,6-ditertpentylphenol

Cas Number:

25973-55-1

Molecular formula:

C22H29N3O

IUPAC Name:

2-(2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylpropyl)phenol

Details on test material:

- Name of test material (as cited in study report): Tinuvin 328
- Batch No.: EN.2299

Method

Target gene:

his operon

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Additional strain / cell type characteristics:

other: histidine-auxotrophic

Metabolic activation:

with and without

Metabolic activation system:

S9 fraction of liver from rats induced with Aroclor 1254 and a solution of co-factors

Test concentrations with justification for top dose:

25, 75, 225, 675, 2025 µg/0.1 ml

Vehicle / solvent:

- solvent used: acetone

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: daunorubicin-HCl (5 & 10 µg/0.1ml phosphate buffer), 4-nitroquinoline-N-oxide (0.125 & 0.25 µg/0.1ml), N-methyl-N'-nitro-N-nitrosoguanidine (3 & 5 µg/0.1ml), 9(5)aminoacridine hydrochloride monohydrate (50 & 100 µg/0.1ml DMSO), no metabolic activation

Controls 2

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

with metbolic activation (only for TA 1535)

Migrated to IUCLID6: 250 µg/0.1 ml

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 h at 37 °C in darkness

NUMBER OF REPLICATIONS: 3 plates each concentration or control group

Evaluation criteria:

A test substance was generally considered to be non-mutagenic if the colony count in relation to the negative control is not doubled at any concentration.

Statistics:

When the colonies had been counted, the arithmetic mean was calculated.

Results and discussion

Test results

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: the concentrations 225, 675, and 2025 µg/0.1 ml precipitated in the soft agar

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Tab. 1 Salmonella/Mammalian-Microsome Mutagenicity Test: Experiments without microsomal activation (Number (arithmetic mean) of colonies of histidine-prototrophic back-mutants)

Results of the test substance

test substance concentration	TA 98	TA 100	TA 1535	TA 1537
control	30	235	9	6
25 µg/0.1 ml	38	226	14	6
75 µg/0.1 ml	26	248	20	9
225 µg/0.1 ml	33	249	16	5
675 µg/0.1 ml	34	248	21	7
2025 µg/0.1 ml	30	248	19	4

Tab. 2: Salmonella/Mammalian-Microsome Mutagenicity Test: Experiments without microsomal activation (Number (arithmetic mean) of colonies of histidine-prototrophic back-mutants)

Results of the positive controls

positive control	concentration	TA 98	TA 100	TA 1535	TA 1537
Daunorubicin-HCl	control	32
	5.0 µg/0.1 ml	727
	10.0 µg/0.1 ml	553
4-Nitroquinoline-N-oxide	control		259
	0.125 µg/0.1 ml		662
	0.25 µg/0.1 ml		>1100
N-Methyl-N'-nitro- N-nitrosoguanidine	control			15
	3 µg/0.1 ml			44
	5 µg/0.1 ml			547
9(5)Aminoacridine hydrochloride	control				6
	50 µg/0.1 ml				39
	100 µg/0.1 ml				388

Tab. 3 Salmonella/Mammalian-Microsome Mutagenicity Test: Experiments with microsomal activation (Number (arithmetic mean) of colonies of histidine-prototrophic back-mutants)

Results of the test substance

test substance concentration	TA 98	TA 100	TA 1535	TA 1537
control	42	201	18	17
25 µg/0.1 ml	32	209	15	13
75 µg/0.1 ml	31	195	18	16
225 µg/0.1 ml	31	207	14	17
675 µg/0.1 ml	43	203	20	13
2025 µg/0.1 ml	48	222	21	19

Tab. 4 Salmonella/Mammalian-Microsome Mutagenicity Test: Experiments with microsomal activation (Number (arithmetic mean) of colonies of histidine-prototrophic back-mutants)

Results of the positive control

positive control	concentration	TA 1535
Cyclophosphamide	control	22
	250 µg/0.1 ml	584
Cyclophosphamide	control	10
	250 µg/0.1 ml	206

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative